LED illumination device for a scannerless range imaging system

1. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system, said illumination device comprising: circuitry for generating a drive signal having given phase and frequency characteristics; a plurality of light emitting diodes arranged in a plurality of LED banks, wherein each LED bank comprises a plurality of light emitting diodes connected in series to the circuitry to receive the drive signal and wherein the plurality of LED banks are arranged on a circuit board in a dispersed fashion such that a bank failure would have minimal impact on the distribution of the illumination; and a switching stage for simultaneously activating the plurality of LED banks such that the LED banks generate the modulated light according to the phase and frequency characteristics of the drive signal.

2. The illumination device as claimed in claim 1 wherein the plurality of LED banks are arranged on a circuit board with the light emitting diodes in a offset placement pattern to provide a more uniform distribution of the output illumination.

3. The illumination device as claimed in claim 1 wherein the light emitting diodes have a peak emission in the infrared region of the spectrum.

4. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system in response to an exposure control signal, said illumination device comprising: an interface circuit for generating a modulating signal in response to the exposure control signal, said modulating signal having given phase and frequency characteristics; a plurality of drive circuits for generating a plurality of drive signals from the modulating signal, whereby each drive signal has the given phase and frequency characteristics; and a plurality of light emitting diodes arranged in a plurality of LED banks, wherein each LED bank comprises a smaller plurality of light emitting diodes connected in series to a given one of the drive circuits to generate the modulated light according to the phase and frequency characteristics of the modulating signal.

5. The illumination device as claimed in claim 4 further comprising a switching stage responsive to the exposure control signal for activating the plurality of drive circuits, thereby activating the plurality of LED banks such that they generate the modulated light according to the phase and frequency characteristics of the modulating signal.

6. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system in response to an exposure control signal, said illumination device comprising: a signal conditioning circuit for processing the exposure control signal into a received clock signal having given phase and frequency characteristics; an interface circuit for converting the received clock signal into a sinusoidal modulating signal having the given phase and frequency characteristics; an LED bank comprising a plurality of light emitting diodes connected in series; a drive circuit for generating a drive signal from the modulating signal for the series-connected light emitting diodes in the LED bank, whereby the drive signal has the given phase and frequency characteristics; means for mounting a plurality of LED banks in a predetermined illumination pattern, wherein each LED bank includes its own series-connected drive circuit and wherein the mounting means arranges the LED banks on a circuit board in a dispersed fashion such that a bank failure would have minimal impact on the distribution of the illumination; and a switching stage responsive to the received clock signal for activating the plurality of light emitting diode banks such that they generate the modulated light according to the given phase and frequency characteristics.

7. The illumination device as claimed in claim 6 wherein the mounting means arranges the LED banks on a circuit board with the light emitting diodes in a offset placement pattern to provide a more uniform distribution of the output illumination.

8. A light emitting diode (LED) illumination device for illuminating a scene for a scannerless range imaging system, said illumination device comprising: circuitry for generating a drive signal having given phase and frequency characteristics; a plurality of light emitting diodes connected to the circuitry to receive the drive signal and illuminate the scene with modulated light in the infrared region of the spectrum having the phase and frequency characteristics of the drive signal; a wide band illumination system for illuminating the scene with unmodulated light, said wide band illumination system comprising a second plurality of light emitting diodes having peak emissions in the visible region of the spectrum; and a switching stage for activating the plurality of light emitting diodes and the wide band illumination system such that they generate their respective light during different intervals.

9. The illumination device as claimed in claim 8 wherein the second plurality of light emitting diodes comprises a plurality of two or more types of visible light diodes emitting in at least two regions of the visible spectrum, and said two or more types of visible light diodes are arrayed in a repetitive pattern including the infrared diodes.

10. The illumination device as claimed in claim 9 wherein the visible light diodes are red, green and blue emitting diodes.

11. A scannerless range imaging camera system for capturing range information from a scene, said system comprising: (a) a camera body including an image responsive element for capturing image light from the scene, a flash unit connection and a lens mount; (b) a light emitting diode (LED) illumination device detachably connected to the flash unit connection of the camera body, said illumination device including an LED illumination section having a plurality of LEDs, an interface section for developing an LED modulating signal and an LED driver section for converting the LED modulating signal into a drive signal for the LEDs, whereby the LED illumination section controllably illuminates the scene with modulated illumination, and some of the modulated illumination is reflected from objects in the scene; (c) an optical component detachably connected to lens mount of the camera body, said optical component establishing an optical path for directing reflected image light, including the modulated illumination, toward the image responsive element; and (d) a modulating element operative in the optical component to modulate the reflected image light with a modulating signal, thereby generating a processed light component captured by the image responsive element with phase data indicative of range information.

12. The range imaging system as claimed in claim 11 wherein the modulating element is a micro-channel plate.

13. The range imaging system as claimed in claim 11 wherein the modulating signal has the same modulating frequency as the LED modulating signal applied to the illumination system.

14. The range imaging system as claimed in claim 11 wherein the image responsive element captures a plurality of images of the reflected modulated illumination, wherein each image incorporates the effect of a predetermined modulation frequency together with a phase offset unique for each image.

15. The range imaging system as claimed in claim 14 wherein each unique phase offset is given by i 2 i/3; i 0, 1, 2.

16. The range imaging system as claimed in claim 11 wherein the image responsive element is a photographic film.

17. The range imaging system as claimed in claim 11 wherein the image responsive element is a digital image sensor.

18. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system in response to an exposure control signal, said illumination device comprising: a signal conditioning circuit for processing the exposure control signal into a received clock signal having given phase and frequency characteristics; an interface circuit for converting the received clock signal into a sinusoidal drive signal having the given phase and frequency characteristics, said interface circuit activated only when the received clock signal is present for more than a predetermined time period; a plurality of light emitting diodes arranged in a plurality of LED banks, wherein each LED bank comprises a plurality of light emitting diodes connected in series to the circuitry to receive the drive signal and generate modulated light and wherein the plurality of LED banks are arranged on a circuit board in a dispersed fashion such that a bank failure would have minimal impact on the distribution of the illumination; a controlled angle diffusion sheet positioned in front of the LED banks to spread the modulated light across a desired field of view; and a switching stage for simultaneously activating the plurality of LED banks such that the LED banks generate the modulated light according to the phase and frequency characteristics of the drive signal.

19. The illumination device as claimed in claim 18 wherein the plurality of LED banks are arranged on a circuit board with the light emitting diodes in a offset placement pattern to provide a more uniform distribution of the output illumination.

20. The illumination device as claimed in claim 18 wherein the light emitting diodes have a peak emission in the infrared region of the spectrum.

21. The illumination device as claimed in claim 18 wherein the controlled angle diffusion plate provides a controlled angle of diffusion of less than about 10 degrees.

22. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system, said illumination device comprising: circuitry for generating a drive signal having given phase and frequency characteristics; a plurality of light emitting diodes arranged in a plurality of LED banks, wherein each LED bank comprises a plurality of light emitting diodes connected in series to the circuitry to receive the drive signal and wherein the plurality of LED banks are arranged on a circuit board with the light emitting diodes in a offset placement pattern to provide a more uniform distribution of the output illumination; and a switching stage for simultaneously activating the plurality of LED banks such that the LED banks generate the modulated light according to the phase and frequency characteristics of the drive signal.

23. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system in response to an exposure control signal, said illumination device comprising: a signal conditioning circuit for processing the exposure control signal into a received clock signal having given phase and frequency characteristics; an interface circuit for converting the received clock signal into a sinusoidal modulating signal having the given phase and frequency characteristics; an LED bank comprising a plurality of light emitting diodes connected in series; a drive circuit for generating a drive signal from the modulating signal for the series-connected light emitting diodes in the LED bank, whereby the drive signal has the given phase and frequency characteristics; means for mounting a plurality of LED banks in a predetermined illumination pattern, wherein each LED bank includes its own series-connected drive circuit and wherein the mounting means arranges the LED banks on a circuit board with the light emitting diodes in an offset placement pattern to provide a more uniform distribution of the output illumination; and a switching stage responsive to the received clock signal for activating the plurality of light emitting diode banks such that they generate the modulated light according to the given phase and frequency characteristics.

24. A light emitting diode (LED) illumination device for generating modulated light for a scannerless range imaging system in response to an exposure control signal, said illumination device comprising: a signal conditioning circuit for processing the exposure control signal into a received clock signal having given phase and frequency characteristics; an interface circuit for converting the received clock signal into a sinusoidal drive signal having the given phase and frequency characteristics, said interface circuit activated only when the received clock signal is present for more than a predetermined time period; a plurality of light emitting diodes arranged in a plurality of LED banks, wherein each LED bank comprises a plurality of light emitting diodes connected in series to the circuitry to receive the drive signal and generate modulated light and wherein the plurality of LED banks are arranged on a circuit board with the light emitting diodes in an offset placement pattern to provide a more uniform distribution of the output illumination; a controlled angle diffusion sheet positioned in front of the LED banks to spread the modulated light across a desired field of view; and a switching stage for simultaneously activating the plurality of LED banks such that the LED banks generate the modulated light according to the phase and frequency characteristics of the drive signal.